Asterosporiaceae Senan., Maharachch. & K.D. Hyde, Stud. Mycol. 86: 236 (2017)

Index Fungorum number: IF821539; 4 species

Endophytic or saprobic on Betulaceae, Fagaceae, Juglandaceae and Sapindaceae. Sexual morph: Undetermined. Asexual morph: Coelomycetous. Conidiomata acervular, subepidermal, erumpent at maturity, solitary, or occasionally confluent, unilocular, dark brown to black. Conidiomata wall composed of thin-walled, brown cells of textura angularis. Conidiophores cylindrical, branched at the base, septate, hyaline to pale brown. Conidiogenous cells holoblastic, cylindrical, unbranched, integrated, determinate, hyaline to pale brown, smooth. Conidia terminal, transversely distoseptate, consisting of four arms, with reduced lumina, brown, smooth-walled (adapted from Senanayake et al. 2017a).

Type genus – Asterosporium Kunze

Notes – Asterosporiaceae is based on the single genus Asterosporium (Senanayake et al. 2017a) and is morphologically distinct from other families in Diaporthales having star-like arms, bearing brown conidia and acervular conidiomata. Asterosporium species occur in temperate regions. We illustrate Asterosporium asterospermum.

Ecological and economic significance of Asterosporiaceae
Cankers and branch dieback of beech may be caused by Asterosporium hoffmannii (Pirone 1978). Sieber (2007) reported that A. asterospermum may cause canker on Fagus crenata and F. sylvatica as mild pathogens. However, most species are saprobes in decaying wood.